added TestZipIteratorStableSort unit test
added TestZipIteratorStableSort unit test

julianromera/thrust,google-code-export/thrust,UIKit0/thrust,UIKit0/thrust,levendlee/thrust,UIKit0/thrust,allendaicool/thrust,malenie/thrust,allendaicool/thrust,rdmenezes/thrust,Vishwa07/thrust,hemmingway/thrust,google-code-export/thrust,bfurtaw/thrust,lishi0927/thrust,bfurtaw/thrust,bfurtaw/thrust,rdmenezes/thrust,h1arshad/thrust,julianromera/thrust,h1arshad/thrust,allendaicool/thrust,levendlee/thrust,bfurtaw/thrust,h1arshad/thrust,hemmingway/thrust,hemmingway/thrust,Vishwa07/thrust,hemmingway/thrust,google-code-export/thrust,malenie/thrust,rdmenezes/thrust,lishi0927/thrust,rdmenezes/thrust,allendaicool/thrust,levendlee/thrust,levendlee/thrust,google-code-export/thrust,h1arshad/thrust,malenie/thrust,Vishwa07/thrust,lishi0927/thrust,julianromera/thrust,UIKit0/thrust,malenie/thrust,Vishwa07/thrust,julianromera/thrust,lishi0927/thrust